Pavlof Harbor
The underwater world of Southeast Alaska is given very little thought from most visitors. We are always excited to behold the size of a humpback whale or the power of brown bears, but what lies beyond the surface is a mystery to most. This morning, after National Geographic Sea Lion eased into her anchorage, I ventured below to capture on film some of the life that this cold, green water keeps from our view. Dazzling amounts of plumed anemones covered nearly every inch of rock on one overhang. Their bodies extended out into passing currents, these animals are collecting nutrients in the form of zooplankton. Coralline algae add a splash of pink to the rocks and sponges contribute yellow. Dusky rockfish appear a radiant indigo under the lights of my video camera. A world that some think is devoid of life is surprisingly colorful and bursting with activity. Because these waters are so productive, a myriad of invertebrates ranging from cucumbers to barnacles pull their nutrients right from the water. Others like rockfish and salmon are higher on the food web but still intimately tied to the primary producing phytoplankton and low level zooplankton.
The conclusion of our voyage in southeast Alaska could not have ended with a bigger crescendo. At Pavlof Harbor we were treated to a true spectacle. In this small, protected bay there runs a small river and in that river run char, pink salmon and dog salmon. If you think people are the only ones that know this, you’d be wrong. Joining us on our afternoon hikes, kayak outings and Zodiac cruises were 4 coastal brown bears. It is here, at this small river that they feast on a bounty that has traveled all the way from the Gulf of Alaska. After spending 2-4 years (depending on the species) out at sea feeding at first upon zooplankton and eventually moving up to other fishes, these salmon have returned to their natal stream with the sole intention of reproducing. These fish spend years and years eating other marine organisms just to have the energy to run up a river, spawn and die, but some of them do not make it.
Watching a bear capture a salmon is so much more than seeing a bear eat a fish. These fish go to sea and after growing big they return with an unmatched tenacity. Their bodies are batteries of stored solar energy, charged by the consumption of fish, which consume zooplankton, which consume phytoplankton, which harness the power of the sun. So as we watched brown bears capturing and eating salmon today, we were seeing years-old energy coming all the way from the Gulf of Alaska, maybe even the Bering Sea, being transferred to a carnivore in the form of fish. We were also watching a forest being fertilized because these marine-based nutrients will be utilized by almost every organism in this ecosystem. In many ways it’s like watching someone trip and fall at the end of a marathon, except when you fall, you get eaten.
Our outstanding experience today would not be possible without a little help from some microscopic plants and animals. Thank the plankton next time you see a bear and maybe think twice before you decide to eat its food.
